JP2016141302A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle which can delay the execution timing of prescribed control when an accelerator return operation having a possibility of accompanying a brake operation immediately thereafter is detected compared with the case that the accelerator return operation is not detected.SOLUTION: A control device for a vehicle comprises: collision prediction time calculation means which calculates a collision prediction time of a front obstacle and an own vehicle on the basis of a distance and a relative speed of the own vehicle with respect to the front obstacle; prescribed control execution means which executes prescribed control for reducing a possibility of a collision of the front obstacle and the own vehicle when the collision prediction time is not longer than a prescribed threshold; and threshold setting means which decreases the prescribed threshold compared with the case that an arrival time is out of a prescribed range when the arrival time of the own vehicle with respect to a current position of the front obstacle is within the prescribed range, and the accelerator return operation is detected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle control device.

  In a rear-end collision warning device for a vehicle that issues a warning when there is a possibility that the host vehicle may collide with a preceding vehicle, it is known that the timing of the warning is made earlier when the accelerator operation is being performed than when it is not. (For example, refer to Patent Document 1).

JP 2013-014225 A

  In the configuration described in Patent Document 1, the configuration described in Patent Document 1 only changes the alarm timing according to the presence or absence of the accelerator operation, and thus is unnecessary while outputting a necessary alarm early. There is room for improvement from the viewpoint of reducing unnecessary warnings. For example, in the configuration described in Patent Document 1, when the accelerator return operation is performed, the alarm timing is uniformly delayed as compared with the state before the accelerator return operation is performed. In this regard, the accelerator return operation does not always involve a brake operation immediately after it, but may also include an accelerator return operation that does not involve a brake operation immediately after. Therefore, it is not preferable to delay the alarm uniformly for the accelerator return operation performed in various driving scenes. This applies not only to alarm control, but also to other controls that reduce the likelihood of collision, such as automatic braking.

  In this regard, when an accelerator return operation is performed when a forward obstacle is present, the possibility that a brake operation is performed immediately after that can be accurately determined based on the distance of the vehicle to the forward obstacle at that time. I understood.

  Therefore, the present invention, when an accelerator return operation is performed when a forward obstacle exists, determines the possibility of a collision between the forward obstacle and the own vehicle based on the distance of the own vehicle to the forward obstacle at that time. It is an object of the present invention to provide a vehicle control device that can delay the execution timing of predetermined control to be reduced.

In order to achieve the above object, according to the present invention, a predicted collision time calculation means for calculating a predicted collision time between the front obstacle and the host vehicle based on the distance and relative speed of the host vehicle with respect to the front obstacle,
Predetermined control execution means for executing predetermined control for reducing the possibility of collision between the front obstacle and the host vehicle when the predicted collision time is equal to or less than a predetermined threshold;
A threshold value setting means for reducing the predetermined threshold value based on a distance (first distance) of the host vehicle with respect to the forward obstacle when an accelerator return operation is detected when the forward obstacle exists. A vehicle control device is provided.

  According to the present invention, when an accelerator return operation is performed when a forward obstacle exists, the possibility of a collision between the forward obstacle and the own vehicle is determined based on the distance of the own vehicle to the forward obstacle at that time. A vehicle control device that can delay the execution timing of the predetermined control to be reduced is obtained.

1 is a diagram showing a vehicle system 1 to which a vehicle control device according to the present invention is applied. It is a figure which shows an example of the threshold value T1 for early appearance, and the threshold value T2 for late appearance. It is a figure which shows the relationship between 1st distance, threshold value T1 for early appearance, and threshold value T2 for late appearance. 10 is a flowchart illustrating an example of a process (part 1) executed by a threshold setting unit 18; 10 is a flowchart illustrating an example of a process (part 2) executed by a threshold setting unit. It is a flowchart which shows an example of the detection method of an accelerator return operation. It is explanatory drawing of the process of FIG. 10 is a flowchart illustrating another example of the process (part 1) executed by the threshold setting unit 18.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a vehicle system 1 to which a vehicle control device according to the present invention is applied. The vehicle system 1 includes a control device (an example of a vehicle control device) 10, an alarm output device 20, a brake 30, a wheel speed sensor 40, and a front detection sensor 50.

  The control device 10 is formed by a computer. An alarm output device 20, a brake 30, a wheel speed sensor 40, and a front detection sensor 50 are connected to the control device 10.

  The alarm output device 20 outputs an alarm by sound and / or display, and includes a buzzer, a display, and the like.

  The brake 30 includes an ECU (Electronic Control Unit) (not shown) and a hydraulic circuit (not shown), and generates a braking force in response to an automatic braking control request from the control device 10. The hydraulic circuit configuration of the brake 30 is a configuration capable of realizing automatic braking control. For example, the hydraulic circuit of the brake 30 includes a pump and an accumulator that generates high-pressure oil. During automatic braking control, various valves and pumps such as a master cylinder cut solenoid valve are controlled so that the wheel cylinder pressure of the wheel cylinder is reduced. The configuration may be such that the pressure is increased. Further, the hydraulic circuit of the brake 30 may have a circuit configuration used in a brake-by-wire system such as ECB (Electric Control Braking).

  The wheel speed sensor 40 detects the rotational speed of the wheel. The wheel speed sensor 40 is disposed on each wheel of the vehicle, for example.

  The accelerator opening sensor 42 detects the accelerator opening (the amount of depression of the accelerator pedal). The accelerator opening sensor 42 supplies information (accelerator opening information) indicating the detection result of the accelerator opening to the control device 10.

  The front detection sensor 50 detects information representing the relationship between the front obstacle and the own vehicle. For example, the front detection sensor 50 detects the state of a front obstacle using radio waves (for example, millimeter waves), light waves (for example, lasers), or ultrasonic waves as detection waves. The front detection sensor 50 detects information indicating the relationship between the front obstacle and the own vehicle, for example, the relative speed, distance, and direction (lateral position) of the front obstacle with reference to the own vehicle at a predetermined cycle. Information representing the relationship between the front obstacle and the host vehicle is transmitted to the control device 10 at a predetermined cycle. The function of the front detection sensor 50 (for example, the position calculation function of the front obstacle) may be realized by the control device 10.

  An image sensor may be used instead of or in addition to the front detection sensor 50. The image sensor includes a camera and an image processing device including an image sensor such as a charge-coupled device (CCD) and a complementary metal oxide semiconductor (CMOS), and recognizes the state of a front obstacle. The camera of the image sensor may be a stereo camera or may include two or more cameras in another manner. Based on the image recognition result, the image sensor detects information indicating a relationship between the front obstacle and the own vehicle, for example, speed and position information of the front obstacle based on the own vehicle at a predetermined cycle. The position information of the front obstacle may include information on the position (distance) of the front obstacle in the front-rear direction of the host vehicle and information on the lateral position of the front obstacle in the lateral direction (width direction). The lateral position of the front obstacle may be calculated based on the lateral center position of the pixel set related to the forward obstacle, or may be calculated as a range between the leftmost lateral position and the rightmost lateral position. Good. Information (detection result) detected by the image sensor may be transmitted to the control device 10 at a predetermined frame period, for example. Note that the image processing function of the image processing apparatus (for example, the position calculation function of the front obstacle) may be realized by the control device 10.

  The control device 10 includes a predicted collision time calculation unit 12, a warning control execution unit 14, a brake control execution unit 16, and a threshold setting unit 18.

  The collision prediction time calculation unit 12 calculates the collision prediction time between the front obstacle and the own vehicle based on information obtained from the front detection sensor 50 (distance and relative speed between the own vehicle and the front obstacle). The collision prediction time is a time remaining until the host vehicle collides with a front obstacle: TTC (Time to Collision). The TTC is derived by dividing the distance to the front obstacle by the relative speed to the front obstacle.

  The alarm control execution unit 14 controls the alarm output device 20. The alarm control execution unit 14 executes alarm control (an example of predetermined control) when the TTC is equal to or less than the first threshold Th1. The alarm control includes outputting an alarm via the alarm output device 20. Note that once an alarm is output because the TTC is equal to or less than the first threshold Th1, the alarm is continuously output for a predetermined time regardless of the relationship between the TTC and the first threshold Th1 thereafter. It's okay.

  The brake control execution unit 16 controls the brake 30. The brake control execution unit 16 executes automatic braking control when the TTC becomes equal to or less than the second threshold Th2. The second threshold Th2 may be the same as the first threshold Th1, but is preferably a value smaller than the first threshold Th1. The automatic braking control is, for example, control for increasing the wheel cylinder pressure of the wheel cylinder in a situation where a driver does not operate a brake pedal (not shown) or in a situation where the amount of operation of the brake pedal is small. . The brake control execution unit 16 outputs an automatic braking control request to the ECU of the brake 30 when the TTC becomes equal to or less than the second threshold Th2. Note that the brake control execution unit 16 may generate the automatic braking control request in such a manner that the braking force increases stepwise.

  When the accelerator returning operation is performed in a situation where there is a front obstacle, the threshold setting unit 18 is based on the distance of the vehicle to the front obstacle at that time (hereinafter also referred to as “first distance”). The first threshold Th1 is decreased. The first distance does not have to be exactly the same distance at the time of detecting the accelerator return operation as long as it substantially represents the distance of the host vehicle to the front obstacle when the accelerator return operation is performed. For example, the first distance may be the same distance immediately before or immediately after detection of the accelerator return operation, depending on the detection method of the accelerator return operation. Details of the threshold setting unit 18 will be described later.

  FIG. 2 is a diagram illustrating an example of the early departure threshold T1 and the late departure threshold T2.

  As shown in FIG. 2, the early departure threshold T1 is larger than the late departure threshold T2. In the example shown in FIG. 2, the early departure threshold value T1 and the late departure threshold value T2 change according to the relative speed. However, the early departure threshold value T1 and the late departure threshold value T2 may be constant regardless of the relative speed, or only a predetermined relative speed range R1 may be set. In the example shown in FIG. 2, the early departure threshold T1 is larger than the delay threshold T2 only in the predetermined relative speed range R1, but may be larger than the delay threshold T2 over the entire relative speed.

  Next, the relationship between the first distance and the early departure threshold value T1 and the late departure threshold value T2 will be described with reference to FIG.

  FIG. 3 is a diagram illustrating the relationship between the first distance and the early departure threshold value T1 and the late departure threshold value T2.

  FIG. 3A shows a method (first method) for switching the early departure threshold T1 and the late departure threshold T2 in accordance with the arrival time based on the first distance.

  The arrival time is the predicted arrival time of the vehicle with respect to the current position of the front obstacle. The arrival time is a predicted value of the time from the present time and the time required to reach the current position of the forward obstacle. Here, when the front obstacle is a stationary object, the arrival time of the own vehicle with respect to the current position of the front obstacle is to divide the distance (first distance) to the front obstacle by the own vehicle speed. Can be derived. In this case, the arrival time is substantially the same as TTC. The vehicle speed can be calculated based on the wheel speed sensor 40. The own vehicle speed may be calculated based on the rotation speed of the output shaft of the transmission instead of the wheel speed sensor 40. In the following, a preceding vehicle is assumed as the front obstacle. In this case, the arrival time is the inter-vehicle time. The inter-vehicle time can be derived by dividing the distance to the preceding vehicle by the own vehicle speed at that time.

  In FIG. 3A, the line C1 is a line with an inter-vehicle time = k1, and the line C2 is a line with an inter-vehicle time = k2 (<k1).

  In the case of the first method, the threshold setting unit 18 sets the first threshold Th1 as the delay threshold T2 when the inter-vehicle time when the accelerator return operation is performed is within the predetermined range S1 having the upper limit value k1. Specifically, the threshold setting unit 18 sets the first threshold when the inter-vehicle time when the accelerator return operation is performed is equal to or greater than k2 (an example of the second predetermined time) and equal to or less than k1 (an example of the first predetermined time). Th1 is set to the delay threshold T2. On the other hand, when the inter-vehicle time when the accelerator return operation is performed is outside the predetermined range S1 (less than k2 or longer than k1), the threshold setting unit 18 sets the first threshold Th1 as the early departure threshold T1. This is because if the accelerator return operation is detected when the inter-vehicle time is not less than k2 and not more than k1, there is a high possibility that the brake operation is immediately followed.

  Therefore, according to the first method, it is possible to delay the execution timing of the alarm control when an accelerator return operation that is likely to be accompanied by a brake operation immediately after is detected, as compared to a case where it is not. That is, if the inter-vehicle time is within the predetermined range S1 (k2 or more and k1 or less) and the accelerator return operation is detected, the driver may have a willingness to decelerate (a decelerating intention to avoid a collision with the preceding vehicle). There is a high possibility that it is accompanied by a brake operation immediately after. On the other hand, when the accelerator return operation is detected when the inter-vehicle time is longer than k1, the driver is not always likely to decelerate, and the possibility that the brake operation is immediately followed is not necessarily high. .

  The inter-vehicle time k1 corresponds to an upper limit value that is considered to be the accelerator return operation for the preceding vehicle. The inter-vehicle time k2 corresponds to the lower limit value of the inter-vehicle time at the time of the accelerator returning operation that can avoid the collision. Since the changeover time from the accelerator pedal to the brake pedal, the depressing force of the brake pedal, and the like may vary depending on the distance of the own vehicle with respect to the preceding vehicle, the value of k2 is varied according to the distance of the own vehicle with respect to the preceding vehicle. May be.

  FIG. 3B shows a method (second method) for switching the early threshold T1 and the late threshold T2 according to the first distance itself. The inter-vehicle distance with respect to the preceding vehicle is a parameter that can be visually recognized by the driver. Based on the inter-vehicle distance (first distance) when the accelerator return operation is performed, the driver intends to decelerate (to avoid a collision with the preceding vehicle). (Deceleration intention) can be accurately determined. The second method is based on this finding.

  In FIG. 3B, the line C3 is a line having a first distance = d1, and the line C4 is a line having a first distance = d2 (<d1). D2 is larger than 0.

  In the case of the second method, the threshold setting unit 18 sets the first threshold Th1 as the delay threshold T2 when the inter-vehicle distance with respect to the preceding vehicle is within the predetermined range S2 having the upper limit value d1 and the accelerator return operation is detected. To do. Specifically, the threshold setting unit 18 sets the first threshold Th1 as the delay threshold T2 when the first distance is not less than d2 (an example of the second predetermined distance) and not more than d1 (an example of the first predetermined distance). Set. On the other hand, when the first distance is outside the predetermined range S2 (less than d2 or longer than d1), the threshold setting unit 18 sets the first threshold Th1 as the early departure threshold T1. This is because, when the accelerator return operation is detected when the inter-vehicle distance with respect to the preceding vehicle is not less than d2 and not more than d1, there is a high possibility that the brake operation is immediately followed. Therefore, similarly to the first method, according to the second method, it is possible to delay the execution timing of the alarm control when an accelerator return operation that is likely to be accompanied by a brake operation immediately after is detected as compared to a case where the accelerator return operation is not performed.

  FIG. 3C shows a method (third method) for switching between the early departure threshold T1 and the late departure threshold T2 in accordance with the first collision prediction time based on the first distance.

  The first collision prediction time corresponds to TTC when the accelerator return operation is performed. The first collision prediction time can be derived by dividing the distance to the front obstacle (first distance) by the relative speed at that time (relative speed to the front obstacle).

In FIG. 3C, the line C5 is a line of TTC = T _TTC1 , and the line C6 is a line of TTC = T _TTC2 (<T _TTC1 ). Note that T _TTC2 is larger than the early departure threshold T1.

In the case of the third method, the threshold setting unit 18 sets the first threshold Th1 to the delay threshold T2 when the TTC is within the predetermined range S3 having the upper limit value T _TTC1 and an accelerator return operation is detected. Specifically, the threshold setting unit 18 determines that the first collision prediction time is _{equal to} or longer than T _TTC2 (an example of the second predetermined collision prediction time) and _{equal to} or _shorter than T _TTC1 (an example of the first predetermined collision prediction time). The threshold value Th1 is set to the delay threshold value T2. On the other hand, when the first collision prediction time is outside the predetermined range S3 (less than _TTTC2 or longer than _TTTC1 ), the threshold setting unit 18 sets the first threshold Th1 as the early departure threshold T1. This is because, when the accelerator return operation is detected when TTC is _{equal to} or greater than T _{TTC2 and} equal to or less than T _TTC1 , there is a high possibility that a brake operation is immediately involved. Therefore, similarly to the first method, according to the third method, the execution timing of the alarm control can be delayed when an accelerator return operation that is likely to be accompanied by a brake operation immediately after is detected as compared to a case where the accelerator return operation is not performed.

  Hereinafter, as a representative example, the case of using the inter-vehicle time will be described in more detail. However, in the following description, “inter-vehicle time” is read as “inter-vehicle distance” or “TTC”, and “predetermined range S1 (same for k1 and k2)” is replaced with “predetermined range S2” or “predetermined range S3”. The case of using the “distance between vehicles” or “TTC” can be realized by re-reading.

  Next, an operation example of the control device 10 will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a flowchart illustrating an example of the process (part 1) executed by the threshold setting unit 18. The process shown in FIG. 4 is executed every predetermined period. In the following description, it is assumed that the various flags have a value of “0” or “1”.

  In step S402, the threshold setting unit 18 determines whether or not the delayed state flag is “0”. The initial value of the delayed state flag is “0”. If the delayed state flag is “1”, the delayed start condition is established and the delayed mode is formed. If the delayed state flag is “0”, the process proceeds to step S404, and otherwise, the process proceeds to step S502 in FIG.

  In step S404, the threshold setting unit 18 determines whether or not an accelerator return operation is detected. For example, the threshold setting unit 18 may determine that the accelerator return operation has been detected based on information from the accelerator opening sensor 42 when the accelerator opening is decreased from a predetermined opening or more to 0. Other determination methods will be described later. If an accelerator return operation is detected, the process proceeds to step S406. Otherwise, the process of the current cycle ends.

  In step S406, the threshold setting unit 18 calculates the inter-vehicle time based on the latest information obtained from the front detection sensor 50 and the like, and determines whether the calculated inter-vehicle time is within the predetermined range S1. The predetermined range S1 is as described above. When there is no preceding vehicle, the inter-vehicle time is an “invalid value” and is determined not to be within the predetermined range S1. If the inter-vehicle time is within the predetermined range S1, the process proceeds to step S408, and otherwise, the process of the current cycle is terminated.

In step S <b> 408, the threshold setting unit 18 determines whether or not other conditions necessary for satisfying the delayed start condition are satisfied. The other conditions are satisfied, for example, when the following conditions (1) to (4) are all satisfied.
(1) The host vehicle speed is less than the predetermined speed V1, and the preceding vehicle speed is less than the predetermined speed V2.
(2) The lateral position of the preceding vehicle is less than the predetermined distance D1.
The condition (1) is set so as to be satisfied when the preceding vehicle is in a deceleration state. The predetermined speeds V1 and V2 may be the same, but the predetermined speed V1 may be greater than the predetermined speed V2. Condition (2) is set to be satisfied when the traveling lane of the preceding vehicle is the same as the traveling lane of the own vehicle. The lateral position of the preceding vehicle can be determined based on information from the front detection sensor 50. In the case of a vehicle having a preceding vehicle following control function such as ACC (Adaptive Cruise Control) or cruise control, it may be added as a further AND condition that the preceding vehicle following control function is in an OFF state. When other conditions necessary for the establishment of the delayed start condition are satisfied, the process proceeds to step S410, and otherwise, the process of the current cycle ends.

  In step S410, the threshold setting unit 18 sets the delayed state flag to “1”.

  In step S412, the threshold setting unit 18 sets the first threshold Th1 as the delay threshold T2. Note that the initial value of the first threshold value Th1 is the early threshold value T1.

  According to the processing shown in FIG. 4, the threshold setting unit 18 sets the first threshold Th1 to the delay threshold T2 when the time between the vehicles relative to the preceding vehicle is within the predetermined range S1 and the accelerator return operation is detected. Set. On the other hand, when the inter-vehicle time of the host vehicle with respect to the preceding vehicle is outside the predetermined range S1, the threshold setting unit 18 maintains the first threshold Th1 at the early departure threshold T1 even when the accelerator return operation is detected. Thereby, it is possible to increase the possibility that unnecessary alarms can be reduced while outputting necessary alarms early.

  In the process shown in FIG. 4, the determination order of steps S404 to S408 is arbitrary. For example, the determination of step S406 may be executed prior to the determination of step S404.

  FIG. 5 is a flowchart illustrating an example of the process (part 2) executed by the threshold setting unit 18.

In step S502, the threshold value setting unit 18 determines whether or not the delayed exit end condition is satisfied. The late exit condition is satisfied, for example, when any of the following conditions (11) to (14) is satisfied.
(11) The host vehicle speed is equal to or higher than the predetermined speed V1, and the preceding vehicle speed is equal to or higher than the predetermined speed V2.
(12) The accelerator opening is not less than the predetermined opening Acc1.
(13) The lateral position of the preceding vehicle is not less than the predetermined distance D1, and the new flag is “1”.
(14) The state where the accelerator opening is zero has continued for a predetermined time.
The condition (11) is set so as to be satisfied when the preceding vehicle is not in a deceleration state. Conditional condition (12) means the end of the driver's intention to decelerate. Condition (13) indicates that the preceding vehicle leaving condition (the leaving condition from the monitoring target) is satisfied. The new flag is set to “1” when a new monitoring target is detected. The condition (14) is provided as a guard condition during casual driving. In the case of a vehicle having a preceding vehicle follow-up control function, it may be added as a further OR condition that the preceding vehicle follow-up control function is on.

  In step S504, the threshold setting unit 18 sets (resets) the first threshold Th1 to the early departure threshold T1.

  In step S506, the threshold setting unit 18 resets the delayed state flag to “0”.

  According to the process shown in FIG. 5, the threshold setting unit 18 returns the first threshold Th1 from the delay threshold T2 to the early threshold T1 when the delay termination condition is satisfied. Thereby, it is possible to suppress the state in which the first threshold value Th1 is set to the delay threshold value T2 from being continued more than necessary, and it is possible to form a state in which a necessary alarm can be output early.

  Next, with reference to FIGS. 6 and 7, a preferred example of a method for detecting the accelerator return operation will be described.

  FIG. 6 is a flowchart illustrating an example of a method for detecting an accelerator return operation. The process shown in FIG. 6 may be executed as the process of step S404 in FIG.

  In step S602, based on the latest information from the accelerator opening sensor 42, the threshold setting unit 18 determines whether or not the accelerator opening is greater than a predetermined ON threshold (hereinafter referred to as “accelerator ON threshold”) Acc2. Determine. The accelerator ON threshold Acc2 is greater than 0 and is a value that can detect the start of the driver's accelerator operation. If the accelerator opening is larger than the accelerator ON threshold Acc2, the process proceeds to step S604, and otherwise, the process proceeds to step S608.

  In step S604, the threshold setting unit 18 determines whether or not the accelerator state flag is “1”. An accelerator state flag of “1” indicates that the accelerator state is on. If the accelerator state flag is “1”, the process is terminated as it is. Otherwise (ie, if the accelerator state flag is “0”), the process proceeds to step S606.

  In step S606, the threshold setting unit 18 sets the accelerator state flag to “1”.

  In step S608, the threshold setting unit 18 determines whether or not the accelerator opening is equal to or less than a predetermined off threshold (hereinafter referred to as “accelerator OFF threshold”) Acc3. The accelerator OFF threshold Acc3 is a value smaller than the accelerator ON threshold Acc2. If the accelerator opening is less than or equal to the accelerator OFF threshold Acc3, the process proceeds to step S610, and otherwise, the process ends.

  In step S610, the threshold setting unit 18 determines whether or not the accelerator state flag is “0”. If the accelerator state flag is “0”, the process is terminated as it is. Otherwise (ie, the accelerator state flag is “1”), the process proceeds to step S612.

  In step S612, the threshold setting unit 18 resets the accelerator state flag to “0”.

  In step S614, the threshold setting unit 18 sets the accelerator return operation detection flag to “1”. The initial value of the accelerator return operation detection flag is “0”. An accelerator return operation detection flag of “1” indicates that an accelerator return operation has been detected. Therefore, when the accelerator return operation detection flag is “1”, the determination result in step S404 is “YES”. The threshold setting unit 18 may reset the accelerator return operation detection flag to “0” after a predetermined time when the accelerator return operation detection flag is set to “1”.

  According to the processing shown in FIG. 6, the threshold setting unit 18 sets the accelerator return operation detection flag to “1” when the accelerator state flag changes from “1” to “0”.

  FIG. 7 is an explanatory diagram of the processing of FIG. 6, and (A) to (C) show different accelerator operation modes. In each of (A) to (C), the time series of changes in the accelerator opening and the relationship between the accelerator ON threshold value Acc2 and the accelerator OFF threshold value Acc3 are shown on the upper side, and the state of the accelerator state flag is shown on the lower side. A timeline is shown.

  FIG. 7A shows a time series of changes in the accelerator opening when the driver completely releases the accelerator pedal and follows the preceding vehicle. In this case, the accelerator state flag changes from “1” to “0” at time t1, and the accelerator return operation is detected. In the example shown in FIG. 7A, at time t2, the accelerator opening exceeds the accelerator ON threshold Acc2 and the accelerator state flag changes from “0” to “1” with the driver's accelerator operation. Yes.

  FIG. 7B shows a time series of changes in the accelerator opening when the driver loosens the accelerator pedal without releasing it completely and follows the preceding vehicle. In this case, the accelerator state flag changes from “1” to “0” at time t1, and the accelerator return operation is detected. At time t2, the accelerator opening exceeds the accelerator ON threshold Acc2 and the accelerator state flag changes from “0” to “1” in accordance with the driver's accelerator operation. From time t1 to time t2, the accelerator opening exceeds the accelerator OFF threshold Acc3 in accordance with the accelerator operation by the driver, but does not exceed the accelerator ON threshold Acc2, and the accelerator state flag is maintained at “0”. Therefore, in a situation where a minute change in the accelerator opening degree without intention to accelerate or decelerate is detected, the accelerator state flag is suppressed from changing (hunting) between “0” and “1” in a short time. The Thereby, it can suppress that accelerator return operation is detected resulting from this hunting.

  FIG. 7C shows a time series of changes in the accelerator opening when the driver does not intend to accelerate. In this case, the accelerator opening does not exceed the accelerator ON threshold Acc2, and the accelerator state flag is maintained at “0”. Therefore, in a situation where a slight increase in the accelerator opening degree without intention to accelerate is detected, the accelerator state flag changes from “0” to “1”, and the accelerator state flag thereafter changes to “1”. The change from “0” to “0” is suppressed. Thereby, it can suppress that accelerator return operation is detected resulting from this change.

  As described above, according to the processing shown in FIG. 6, by setting the accelerator ON threshold value Acc2 and the accelerator OFF threshold value Acc3 separately (by not setting the same value), it is possible to accurately detect the accelerator return operation accompanied by the intention to decelerate. . Thereby, it is possible to further increase the possibility that unnecessary alarms can be reduced while outputting necessary alarms early.

  Next, another operation example of the control device 10 will be described with reference to FIG.

  FIG. 8 is a flowchart illustrating an example of the process (part 1) executed by the threshold setting unit 18. The process shown in FIG. 8 is executed every predetermined period. The process shown in FIG. 8 is executed as an alternative to the process shown in FIG.

  The process shown in FIG. 8 is different from the process shown in FIG. 4 in that steps S802 to S810 are added.

  In step S802, the threshold setting unit 18 determines whether or not the accelerator state is an on state. For example, the threshold setting unit 18 may determine that the accelerator is on when the accelerator opening is larger than the accelerator ON threshold Acc2 (see the description of FIG. 6). If the accelerator state is on, the process proceeds to step S804. Otherwise, the process proceeds to step S806.

  In step S804, the threshold setting unit 18 determines whether or not the current first threshold Th1 is not the early departure threshold T1. If the current first threshold Th1 is not the early departure threshold T1, the process proceeds to step S806, and if the current first threshold Th1 is the early departure threshold T1, the process ends.

  In step S806, the threshold setting unit 18 sets the first threshold Th1 as the early departure threshold T1.

  In step S808, it is determined whether the current first threshold value Th1 is not the normal threshold value T3. If the current first threshold value Th1 is not the normal threshold value T3, the process proceeds to step S810. If the current first threshold value Th1 is the normal threshold value T3, the process ends.

  In step S806, the threshold setting unit 18 sets the first threshold Th1 to the normal threshold T3. The normal threshold T3 is a value smaller than the early departure threshold T1 and larger than the late departure threshold T2.

  According to the process shown in FIG. 8, the threshold setting unit 18 sets the first threshold Th1 to the delay threshold T2 when the time between the vehicles relative to the preceding vehicle is within the predetermined range S1 and the accelerator return operation is detected. Set. On the other hand, the threshold setting unit 18 sets the first threshold Th1 to the early departure threshold T1 or the normal threshold T3 according to the accelerator state when the inter-vehicle time of the host vehicle with respect to the preceding vehicle is outside the predetermined range S1. That is, when the accelerator state is the on state, the first threshold value Th1 is set to the early departure threshold value T1, and in other cases, the first threshold value Th1 is set to the normal threshold value T3. Thereby, when an accelerator state is an ON state, possibility that a warning will be output earlier compared with the case other than that increases. Thereby, it is possible to increase the possibility that unnecessary alarms can be reduced while outputting necessary alarms early.

  In the example illustrated in FIG. 8, the first threshold Th1 is switched between three values (T1 to T3), but may be switched between four or more values, or may be switched in another manner. Also good. For example, a threshold value T4 (<T2) for brake operation may be prepared, and the threshold value setting unit 18 may set the first threshold value Th1 to the threshold value T4 when the brake operation is detected.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the threshold setting unit 18 sets the first threshold Th1 as the early departure threshold T1 when the accelerator return operation is detected when the inter-vehicle time is less than the lower limit k2. This is because when the inter-vehicle time is less than the lower limit value k2, the alarm is likely to be useful because the inter-vehicle time is short, regardless of whether or not the driver intends to decelerate. However, the threshold setting unit 18 may set the first threshold Th1 as the delay threshold T2 when the accelerator return operation is detected when the inter-vehicle time is less than the lower limit value k2.

  In the present embodiment, the threshold setting unit 18 does not change the second threshold Th2 based on the inter-vehicle time or the like, unlike the first threshold Th1, but the second threshold Th2 is the same as the first threshold Th1. It may be variable. In other words, the above-described features relating to alarm control can be applied to automatic braking control (another example of predetermined control). Specifically, the threshold setting unit 18 sets the second threshold Th2 as the delay threshold T4 when the inter-vehicle time is within the predetermined range S1 (k2 or more and k1 or less) and an accelerator return operation is detected. On the other hand, when the inter-vehicle time is outside the predetermined range S1 (less than k2 or longer than k1) or the accelerator return operation is not detected, the threshold setting unit 18 sets the second threshold Th2 to the early departure threshold T3 (> T4). Set. Note that the second threshold Th2 (T3, T4) set under a certain situation may be a value smaller than the first threshold Th1 (T1, T2) set under the same situation.

  Moreover, although the brake control execution part 16 is provided in the Example mentioned above, the brake control execution part 16 may be abbreviate | omitted.

  In the example illustrated in FIG. 8, if the determination result in step S <b> 802 is “NO”, it is determined that the accelerator state is not on, and the process proceeds to step S <b> 808, but is not limited thereto. For example, in step S802, the threshold setting unit 18 determines whether or not the accelerator opening is larger than the accelerator ON threshold Acc2. If the determination result is “NO”, instead of proceeding to step S808. Further, it may be determined whether or not the accelerator opening is equal to or less than the accelerator OFF threshold Acc3. In this case, when the accelerator opening is equal to or less than the accelerator OFF threshold Acc3, the process proceeds to step S808, and otherwise, the process is terminated as it is.

DESCRIPTION OF SYMBOLS 1 Vehicle system 10 Control apparatus 12 Collision prediction time calculation part 14 Alarm control execution part 16 Brake control execution part 18 Threshold setting part 20 Alarm output device 30 Brake 40 Wheel speed sensor 42 Accelerator opening degree sensor 50 Front detection sensor

Claims (9)

A collision prediction time calculation means for calculating a collision prediction time between the front obstacle and the vehicle based on the distance and relative speed of the vehicle with respect to the front obstacle;
Predetermined control execution means for executing predetermined control for reducing the possibility of collision between the front obstacle and the host vehicle when the predicted collision time is equal to or less than a predetermined threshold;
When an accelerator return operation is performed when the front obstacle is present, the predetermined threshold value is reduced based on the distance of the host vehicle to the front obstacle at that time (hereinafter referred to as “first distance”). A vehicle control device comprising: threshold setting means for performing the operation.   2. The vehicle control device according to claim 1, wherein when the first distance is equal to or less than a first predetermined distance, the threshold setting unit decreases the predetermined threshold as compared with a case where the first distance is not the first predetermined distance.   2. The threshold value setting unit reduces the predetermined threshold value when the first distance is greater than or equal to a second predetermined distance greater than 0 and less than or equal to the first predetermined distance, as compared with a case where the first distance is not. Vehicle control device.   The threshold setting means reduces the predetermined threshold when the arrival time obtained by dividing the first distance by the own vehicle speed at the same time is equal to or shorter than a first predetermined time, compared to the case where it is not. Item 4. The vehicle control device according to Item 1.   The threshold value setting means determines whether the arrival time obtained by dividing the first distance by the vehicle speed at the same time is greater than or equal to a second predetermined time greater than 0 and less than or equal to the first predetermined time. The vehicle control device according to claim 1, wherein the predetermined threshold value is made smaller than that of the vehicle control device.   The threshold setting means has a first collision prediction time obtained by dividing the first distance by the relative speed at the same point, which is equal to or longer than a second predetermined collision prediction time that is greater than the maximum value of the predetermined threshold. 2. The vehicle control device according to claim 1, wherein the predetermined threshold value is made smaller when the time is equal to or shorter than the predetermined collision prediction time, as compared with a case where it is not.   The threshold value setting means increases the predetermined threshold value when an accelerator operation is performed under a situation other than a situation where the predetermined threshold value is reduced, compared to a case where the accelerator operation is not performed. The vehicle control device according to claim 1.   The threshold setting means detects an accelerator return operation when the accelerator opening is equal to or less than a predetermined off threshold smaller than the predetermined on threshold from a state where the accelerator opening exceeds a predetermined on threshold. The vehicle control device according to any one of claims 1 to 7. In a vehicle control device that executes predetermined control to reduce the possibility when there is a possibility of collision between a front obstacle and the host vehicle,
(1) The distance of the vehicle to the current position of the front obstacle,
(2) a first time obtained by dividing the distance by the current vehicle speed, or
(3) a second time obtained by dividing the distance by the current relative speed of the vehicle with respect to the forward obstacle;
However, when the accelerator return operation is performed when it is within a predetermined range having an upper limit value, the vehicle control device delays the execution timing of the predetermined control as compared to the case where the accelerator return operation is not performed.

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